JPS58199775A - Semipermeable ceramics and manufacture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to semipermeable membrane ceramics and a method for producing the same.

At present, a semipermeable membrane that is controlled by particle size has not been found to have a material that allows the particle size to be freely controlled, or a semipermeable membrane that selects between anions and cations.

Some semipermeable membranes are made of polymers, but they are very expensive.

An object of the present invention is to provide semipermeable membrane ceramics that can control the diameter of permeable particles within a wide range and are inexpensive, as well as a method for producing the same.

The present invention will be explained in detail below.

The raw materials include powdered ZnOy-0.5 to 20 mole percent Bi, O, and 0.05 to 2.0 mole percent. Q mole percent sb,o, O,OS ~ 0.3 mole percent CrOB, and 0.005 ~ 0.3-F nyl percent wo.

are added, mixed well, and then molded. This molded body is 90
After sintering at 0℃~120G, 0.2~ll! Polish to l thickness. Next, the sintered body is heated at 150 to 300°C per hour.
Heat up to 1300"C to 1450℃ with a heating speed of 0.
．． Hold for 5-3 hours, then reduce from 150-b temperature to 10
Cool slowly to below 0°C.

By this heat treatment after firing, Bl and O are volatilized, resulting in a microporous sintered body with thermal distortion removed.

That is, general sintering of the ZnO-based element is performed using the ZnO-B1101-8blO1-Cr10g system, and the Bi, O, and O layers are stabilized by the trace amount of WO added.

Then, by high-speed, high-temperature heat treatment after adjusting the size, Bi and O, which are not stabilized in terms of crystal structure, volatilize and become microporous. The diameter of the permeated particles can be controlled by the holding temperature and time of the cage. In addition, the permeation average particle diameter and micropore density are controlled by the primary firing temperature, the amount of Bi, O, and the amount of 'wo, sb, o, added, but the most effective means are the former two, O. Note that if the Bi, O, concentration is lower than the above concentration, a sufficiently porous ceramic cannot be obtained, and if it is too high, the ceramic becomes brittle. sb, o, .

If Cr1O1 is less than the above concentration, the structure of the grain boundary layer of one ZnO particle will not be sufficiently formed, and conversely, if it is too much, the growth of ZnO particles will be suppressed. WO, is too small and Bi, Os
will volatilize too much, and if it is too much, a sufficiently porous ceramic will not be obtained. Furthermore, the -next firing is 900'
If the temperature exceeds the range of C to 1200°C, the sinterability will be unsatisfactory, and if the porous treatment exceeds the range of 1300 to 1450°C, effective treatment will not be possible.As an experiment based on the present invention, 97.7 mol of ZnO was used. Percent, Bi, O, 1
．． 9 mol percent, Sb, O, 1.0 mol percent, (!rlo1 0.2 mol percent/), WO, 40
The material ratio was set to 1 mole percent, and the sintered body was sintered according to the firing pattern shown in Figure 1 (A), and the sintered body was heated to 0.51E.
The ceramics polished to I thickness and subjected to the high-temperature heat treatment shown in Figure 1 (B) in the same manner as described above has an average permeation grain size of 40A as measured by the mercury injection processing method, and an average number of permeation holes of 1.
0'/cI/l was realized.

FIG. 2 shows experimental results showing that the average permeation particle size and average number of semipermeable membrane ceramics can be controlled by conditions such as high-temperature heat treatment in the present invention.

The same figure (A) shows the firing pattern in the above experiment. , is 1200℃ (Al is used,
The high temperature heat treatment pattern is shown in Figure 1 (B) at a holding temperature of 1.
It shows the change in average particle size when the temperature of the grain is changed from 1300°C to 1450°C. Figure 2 (Bl is the same figure) shows the change in biological particle size when the holding temperature in AR is 1000°C and the holding time is carefully selected.

Figure 2 (0) shows the change in average grain size when the heat treatment is the same and the firing degree T1 is changed.

Also, in the same figure) shows the particle size distribution in the above experiment.

Figure 2 (El is Bi, O, shows the change in average particle size and average number when changing 431 degrees, and the conditions are calcination temperature [
T s is 1000℃ for 2 hours, high temperature heat treatment is 135oC
This is the case where the time is 1 hour. In the figure, characteristic (a) (+7(
b) is wo, 0.1 mole percent, (c) and, to)
is the case where wo is set to (M) 1 mol percent.

It is clear from these experimental examples that #B
This can be achieved by adjusting the amount and firing and heat treatment temperatures, and it is relatively easy to control, and the material is ceramic, which is inexpensive. The particle size control range is from 35mm to about 10mm.
It is possible to realize a wide range of porous ceramics up to 0 oR.

[Brief explanation of drawings]

Figure 1 shows the firing and heat treatment temperature patterns in the present invention;
FIG. 2 is a control characteristic diagram of average particle diameter, etc. in the present invention. \、

Claims (1)

[Claims] (1177,4 to 99.4 mol percent ZnO;
0,5-20 mole percent Bi, Os, and O,O
S~2.0-fk par-7t 8b, O, and O,
OS −0.3 mole percent Oro 01 and o, o
os ~ 0,3 mole percent To,,! : Semipermeable membrane ceramics characterized by being sintered with raw materials containing. (2177,4-994 mol percent ZnO and 0
0.5 to 20 mole percent inhibition. and O,OS~2.
0 mole percent Sbl O, and 0.05 to 0.3
A raw material containing mol percent of 0r10B and 0005 to 0.3 mol percent of WO is mixed and molded. After firing at 900℃~1200℃ for 1~6 hours, 130℃
A method for producing semipermeable membrane ceramics, which comprises performing a high-temperature heat treatment at 0 to 1450°C. (3) In accordance with claim 2, the high l heat treatment is performed by heating the fired body at a heating rate of 150 to 300°C per hour.
After heating to 300 to 1450℃ and maintaining this heating state for a predetermined time, cooling to 600℃ at a cooling rate of 150 to 300℃ per hour, and from 600℃ to 1 hour @ 910℃
A method for producing semipermeable membrane ceramics, characterized by slow cooling at a temperature decreasing rate of 0°C.